Stable cell platform

ABSTRACT

A stable platform supports a cell, the stable platform comprises a lower mainframe, an upper mainframe, and a dampener system. The upper mainframe includes a plurality of recesses. Each recess is configured to receive a cell. The dampener system connects the lower mainframe to the upper mainframe. In one embodiment, the dampener system comprises a dampener element, such as sand, to dampen vibrations between the lower mainframe and the lower mainframe.

CONTINUATION INFORMATION

This is a continuation-in-part of prior filed U.S. patent applicationSer. No. 09/289,074, filed Apr. 8, 1999 now U.S. Pat. No. 6,258,220, andentitled “ELECTRO-CHEMICAL DEPOSITION SYSTEM”.

This is a continuation-in-part of prior filed U.S. patent applicationSer. No. 09/350,210, filed Jul. 9, 1999 now U.S. Pat. No. 6,267,853, andentitled “ELECTRO-CHEMICAL DEPOSITION SYSTEM”.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a support structure. Moreparticularly, the present invention relates to the mainframe to supporta process cell.

2. Background of the Related Art

Electroplating, previously limited in integrated circuit design to thefabrication of lines on circuit boards, is now used to deposit metalfilms, such-as copper, on substrates to form interconnect features, e.g.vias, trenches, or contacts. One feature filling embodiment thatutilizes electroplating requires initially depositing a diffusionbarrier layer on the substrate by a process such as physical vapordeposition (PVD) or chemical vapor deposition (CVD). A seed layer isdeposited on the substrate by PVD or CVD to define a plating surface. Ametal film is then deposited by electroplating on the seed layer. Theseed layer is typically formed from the same metal as the subsequentlyelectroplated metal film, so the seed layer becomes contiguous with themetal film. Finally, the deposited metal film can be planarized byanother process, e.g., chemical mechanical polishing (CMP), to define aconductive interconnect feature. Electroplating is performed byestablishing a voltage/current level between the seed layer on thesubstrate and a separate anode to deposit metal ions on the seed layer.

Such PVD, CVD, electroplating, CMP, or other operations associated withsemiconductor processing require a stable platform. In electroplating,for example, any vibration/motion that is transferred to an electrolytecell can be transferred to the electrolyte solution contained within theelectrolyte cell. Such vibration/motion of the electrolyte solutionwithin the electrolyte cell can effect the uniformity of the metal filmthat is deposited on the seed layer during electroplating. Otherprocesses such as CVD or PVD are also adversely effected by vibrationand/or motion of the cell of the processing chamber carrying out theparticular process during processing.

Robots are often used in conjunction with processing systems such asthose that perform electroplating, PVD, CVD, or CMP operations. Therobots are accurately aligned with the process cells to effect transferof the substrate from a robot blade in which the robot blade supportsthe substrate, to the process cell, or a substrate holder systemassociated with the cell. Modern systems are designed so multiplesubstrate can be processed in identical, though different, process cellssimultaneously to increase processing throughput. The robots aretherefore often required to simultaneously transfer multiple substratesbetween multiple sets of cells. To provide for such simultaneoustransfer of multiple substrates between multiple sets of process cells,all of the robots are correctly aligned with the appropriate sets ofprocess cells. Such alignment is compromised by anyvibration/displacement that occurs between the robot and the processcell, or the substrate holder system associated with the process cell.

Therefore, there remains a need for a stable cell platform to supportprocess cells, metrology cells, SRD cells, etc. The stable platformshould preferably limit displacement/vibration between the platform andthe cell.

SUMMARY OF THE INVENTION

The present invention generally provides an electro-chemical plating(ECP) system. More particularly, the ECP system includes a stableplatform comprising a lower mainframe, an upper mainframe, and adampener system. The upper mainframe includes a plurality of recesses.Each recess is configured to receive a cell. The dampener systemconnects the lower mainframe to the upper mainframe.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features, advantages andobjects of the present invention are attained can be understood indetail, a more particular description of the invention, brieflysummarized above, may be had by reference to the embodiments thereofwhich are illustrated in the appended drawings.

FIG. 1 is a simplified cross sectional view of a typical fountain platerincorporating contacts;

FIG. 2 is a perspective view of one embodiment of an electroplatingsystem platform;

FIG. 3 is a schematic view of the electroplating system platform of FIG.2;

FIG. 4 is a schematic perspective view of one embodiment of aspin-rinse-dry (SRD) module, incorporating rinsing and dissolving fluidinlets;

FIG. 5 is a side cross sectional view of the spin-rinse-dry (SRD) moduleof FIG. 4 and shows a substrate in a processing position disposedbetween fluid inlets;

FIG. 6 is a cross sectional view of one embodiment of an electroplatingprocess cell;

FIG. 7 is a partial cross sectional perspective view of one embodimentof a cathode contact ring;

FIG. 8 is a cross sectional perspective view of the cathode contact ringshowing an alternative embodiment of the contact pads;

FIG. 9 is a cross sectional perspective view of the cathode contact ringshowing an alternative embodiment of the contact pads and an isolationgasket;

FIG. 10 is a cross sectional perspective view of the cathode contactring showing the isolation gasket;

FIG. 11 is a simplified schematic diagram of one embodiment ofelectrical circuit representing the electroplating system through eachcontact;

FIG. 12 is a cross sectional view of one embodiment of a substrateholder assembly;

FIG. 12A is an enlarged cross sectional view of one embodiment of thebladder area of FIG. 12;

FIG. 13 is a partial cross sectional view of one embodiment of asubstrate holder plate;

FIG. 14 is a partial cross sectional view of one embodiment of amanifold;

FIG. 15 is a partial cross sectional view of one embodiment of abladder;

FIG. 16 is a schematic diagram of one embodiment of an electrolytesolution replenishing system;

FIG. 17 is a cross sectional view of one embodiment of a rapid thermalanneal (RTA) chamber;

FIG. 18 is a perspective view of an alternative embodiment of oneembodiment of a cathode contact ring;

FIG. 19 is a partial cross sectional view of an alternative embodimentof one embodiment of a substrate holder assembly;

FIG. 20 is a cross sectional view of one embodiment of an encapsulatedanode;

FIG. 21 is a cross sectional view of another embodiment of anencapsulated anode;

FIG. 22 is a cross sectional view of another embodiment of anencapsulated anode;

FIG. 23 is a cross sectional view of yet another embodiment of anencapsulated anode;

FIG. 24 is a top schematic view of one embodiment of a mainframetransfer robot having a flipper robot incorporated therein;

FIG. 25 is an alternative embodiment of the process head assembly havinga rotatable head assembly;

FIGS. 26 a and 26 b are cross sectional views of embodiments of adegasser module;

FIG. 27 is a top view of one embodiment of an upper mainframe;

FIG. 28 is a perspective view of one embodiment of a lower mainframe anda dampener system;

FIG. 29 is a top view of one embodiment of rigidifying plate as shown inFIG. 27; and

FIG. 30 is a side view of a portion of the embodiment of a lowermainframe and a dampener system shown in FIG. 28.

The terms “below”, “above”, “bottom”, “top”, “up”, “down”, “upper”, and“lower” and other positional terms used herein are shown with respect tothe embodiments in the figures and may be varied depending on therelative orientation of the processing apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

One aspect of the invention relates to a stable platform that supports acell. The cell may be a process cell such as an electroplating cell, achemical vapor deposition (CVD) cell, or a physical vapor deposition(VD) cell. Alternatively, the cell may be metrology station cell, aspin-rinse-dry (SRD) module cell, etc. The stable platform that supportsthe cell comprises a lower mainframe, an upper mainframe, and a dampenersystem. The dampener system connects the lower mainframe to the uppermainframe, and dampens the vibrations therebetween. The cells areconfigured to fit within a recess formed within the upper mainframe.

In this disclosure, one embodiment of an electroplating system thatcould utilize the stable platform is described. The structure andoperation of the stable platform is also described. Although embodimentsare described with reference to an electroplating system, it isunderstood that the electroplating system is not limited to suchsystems.

1. Electroplating System and Operation

FIG. 1 shows one embodiment of fountain plater 10 used inelectroplating. The fountain plater 10 includes an electrolyte cell 12,a substrate holder system 14, an anode 16, and a contact ring 20. Theelectrolyte cell 12 contains electrolyte solution, and the electrolytecell has a top opening 21 circumferentially defined by the contact ring20. The substrate holder system 14 is disposed above the electrolytecell, and is capable of displacing the substrate to be immersed into,and out of, the electrolyte solution. Portions of the substrate holdersystem enter, and exit the electrolyte solution through the top openingof the electrolyte cell. The substrate holder system 14 is also capableof securing and positioning the substrate in a desired position withinthe electrolyte solution during processing. The contact ring 20comprises a plurality of metal or metal alloy electrical contacts thatelectrically contact the seed layer on the substrate. A controller 23 iselectrically connected to the contacts and to the anode, and thecontroller provides an electrical current to the substrate when the seedlayer on the substrate is being plated. The controller therebydetermines the electrical current/voltage established across from theanode to the seed layer on the substrate.

FIG. 2 is a perspective view of an electroplating system platform 200.FIG. 3 is a schematic view of the electroplating system platform 200.Referring to both FIGS. 2 and 3, the electroplating system platform 200generally comprises a loading station 210, a rapid thermal anneal (RTA)chamber 211, a spin-rinse-dry (SRD) station 212, a mainframe 214, and anelectrolyte solution replenishing system 220. Preferably, theelectroplating system platform 200 is enclosed in a clean environmentusing panels such as PLEXIGLAS® (a registered trademark of the Rohm AndHaas Company, West Philadelphia, Pa.). The mainframe 214 generallycomprises a mainframe transfer station 216 and a plurality of processingstations 218. Each processing station 218 includes one or more processcells 240. An electrolyte solution replenishing system 220 is positionedadjacent the electroplating system platform 200 and connected to theprocess cells 240 individually to circulate electrolyte solution usedfor the electroplating process. The electroplating system platform 200also includes a controller 222, typically comprising a programmablemicroprocessor.

The controller 222 comprises a central processing unit (CPU) 260, memory262, circuit portion 265, input output interface (I/O) 279, and bus (notshown). The controller 222 may be a general-purpose computer, amicroprocessor, a microcontroller, or any other known suitable type ofcomputer or controller. The CPU 260 performs the processing andarithmetic operations for the controller 222. The controller 222controls the processing, robotic operations, timing, etc. associatedwith the electroplating system platform 200. The controller controls thevoltage applied to the anode 16, the plating surface 15 of the substrate22, and the operation of the substrate holder assembly 450 as shown inFIG. 6.

The memory 262 includes random access memory (RAM) and read only memory(ROM) that together store the computer programs, operands, operators,dimensional values, system processing temperatures and configurations,and other parameters that control the electroplating operation. The busprovides for digital information transmissions between CPU 260, circuitportion 265, memory 262, and I/O 279. The bus also connects I/O 279 tothe portions of the ECP system 200 that either receive digitalinformation from, or transmit digital information to, controller 222.

I/O 279 provides an interface to control the transmissions of digitalinformation between each of the components in controller 222. I/O 279also provides an interface between the components of the controller 222and different portions of the ECP system 200. Circuit portion 265comprises all of the other user interface devices, such as display andkeyboard.

In this disclosure, the term “substrate” is intended to describesubstrates, wafers, or other objects that can be processed within theelectroplating system platform 200. The substrates are generallycylindrical or rectangular in configuration, and may include suchirregularities as notches or flatted surfaces that assist in processing.The loading station 210 preferably includes one or more substratecassette receiving areas 224, one or more loading station transferrobots 228 and at least one substrate orientor 230. The number ofsubstrate cassette receiving areas, loading station transfer robots 228and substrate orientor included in the loading station 210 can beconfigured according to the desired throughput of the system. As shownfor one embodiment in FIGS. 2 and 3, the loading station 210 includestwo substrate cassette receiving areas 224, two loading station transferrobots 228 and one substrate orientor 230. A substrate cassette 232containing substrates 234 is loaded onto the substrate cassettereceiving area 224 to introduce substrates 234 into the electroplatingsystem platform. The loading station transfer robot 228 transferssubstrates 234 between the substrate cassette 232 and the substrateorientor 230. The loading station transfer robot 228 comprises a typicaltransfer robot commonly known in the art. The substrate orientor 230positions each substrate 234 in a desired orientation to ensure that thesubstrate is properly processed. The loading station transfer robot 228also transfers substrates 234 between the loading station 210 and theSRD station 212 and between the loading station 210 and the thermalanneal chamber 211.

FIG. 4 is a schematic perspective view of a spin-rinse-dry (SRD) module,incorporating rinsing and dissolving fluid inlets. FIG. 5 is a sidecross sectional view of the spin-rinse-dry (SRD) module of FIG. 4 andshows a substrate in a processing position disposed between fluidinlets. Preferably, the SRD station 212 includes one or more SRD modules236 and one or more substrate pass-through cassettes 238. Preferably,the SRD station 212 includes two SRD modules 236 corresponding to thenumber of loading station transfer robots 228, and a substratepass-through cassette 238 is positioned above each SRD module 236. Thesubstrate pass-through cassette 238 facilitates substrate transferbetween the loading station 210 and the mainframe 214. The substratepass-through cassette 238 provides access to and from both the loadingstation transfer robot 228 and a robot in the mainframe transfer station216.

Referring to FIGS. 4 and 5, the SRD module 236 comprises a bottom 330 aand a sidewall 330 b, and an upper shield 330 c which collectivelydefine a SRD module bowl 330 d, where the shield attaches to thesidewall and assists in retaining the fluids within the SRD module.Alternatively, a removable cover could also be used. A pedestal 336,located in the SRD module, includes a pedestal support 332 and apedestal actuator 334. The pedestal 336 supports the substrate 338 shownin FIG. 5 on the pedestal upper surface during processing. The pedestalactuator 334 rotates the pedestal to spin the substrate and raises andlowers the pedestal as described below. The substrate may be held inplace on the pedestal by a plurality of clamps 337. The clamps pivotwith centrifugal force and engage the substrate preferably in the edgeexclusion zone of the substrate. In a preferred embodiment, the clampsengage the substrate only when the substrate lifts off the pedestalduring the processing. Vacuum passages (not shown) may also be used aswell as other holding elements. The pedestal has a plurality of pedestalarms 336 a and 336 b, so that the fluid through the second nozzle mayimpact as much surface area on the lower surface on the substrate as ispractical. An outlet 339 allows fluid to be removed from the SRD module.

A first conduit 346, through which a first fluid 347 flows, is connectedto a valve 347 a. The conduit may be hose, pipe, tube, or other fluidcontaining conduits. The valve 347 a controls the flow of the firstfluid 347 and may be selected from a variety of valves including aneedle, globe, butterfly, or other valve types and may include a valveactuator, such as a solenoid, that can be controlled with a controller222. The conduit 346 connects to a first fluid inlet 340 that is locatedabove the substrate and includes a mounting portion 342 to attach to theSRD module and a connecting portion 344 to attach to the conduit 346.The first fluid inlet is shown with a single first nozzle 348 to delivera first fluid 347 under pressure onto the substrate upper surface.However, multiple nozzles could be used and multiple fluid inlets couldbe positioned about the inner perimeter of the SRD module. Preferably,nozzles placed above the substrate should be outside the diameter of thesubstrate to lessen the risk of the nozzles dripping on the substrate.The first fluid inlet 340 could be mounted in a variety of locations,including through a cover positioned above the substrate. Additionally,the nozzle 348 may articulate to a variety of positions using anarticulating member 343, such as a ball and socket joint.

Similar to the first conduit and related elements described above, asecond conduit 352 is connected to a control valve 349 a and a secondfluid inlet 350 with a second nozzle 351. The second fluid inlet 350 isshown below the substrate and angled upward to direct a second fluidunder the substrate through the second nozzle 351. Similar to the firstfluid inlet 340, the second fluid inlet may include a plurality ofnozzles 348, a plurality of fluid inlets and mounting locations, and aplurality of orientations including using the articulating member 353.Each fluid inlet could be extended into the SRD module at a variety ofpositions. For instance, the flow can be adjusted to direct fluid at thesubstrate at any prescribed angle toward, or away from, the periphery ofthe SRD module depending upon the desired etching or rinsing action.

The controller 222 could individually control the two fluids and theirrespective flow rates, pressure, and timing, and any associated valving,as well as the spin cycle(s). The controller could be remotely located,for instance, in a control panel or control room and the plumbingcontrolled with remote actuators. An alternative embodiment, shown indashed lines, provides an auxiliary fluid inlet 346 a connected to thefirst conduit 346 with a conduit 346 b and having a control valve 346 c.The alternate embodiment may be used to flow a rinsing fluid on thebackside of the substrate after the dissolving fluid is applied. Therinsing fluid may be applied without having to reorient the substrate orswitch the flow through the second fluid inlet to a rinsing fluid.

In one embodiment, the substrate is mounted with the deposition surfaceof the disposed face up in the SRD module bowl. As will be explainedbelow, for such an arrangement, the first fluid inlet 340 wouldgenerally flow a rinsing fluid, typically deionized water or alcohol.Consequently, the backside of the substrate would be mounted facing downand a fluid flowing through the second fluid inlet would be a dissolvingfluid, such as an acid, including hydrochloric acid, sulfuric acid,phosphoric acid, hydrofluoric acid, or other dissolving liquids orfluids, depending on the material to be dissolved. Alternatively, thefirst fluid and the second fluid are both rinsing fluids, such asdeionized water or alcohol, when the desired process is to rinse theprocessed substrate.

In operation, the pedestal is in a raised position, shown in FIG. 4, anda robot, not shown, places the substrate, front side up, onto thepedestal. The pedestal lowers the substrate to a processing positionwhere the substrate is vertically disposed between the first and thesecond fluid inlets. Generally, the pedestal actuator rotates thepedestal between about 5 to about 5000 rpm, with a typical range betweenabout 20 to about 2000 rpm for a 200 mm substrate. The rotation causesthe lower end 337 a of the clamps to rotate outward about pivot 337 b,toward the periphery of the SRD module sidewall, due to centrifugalforce. The clamp rotation forces the upper end 337 c of the clamp inwardand downward to center and hold the substrate 338 in position on thepedestal 336, preferably along the substrate edge. The clamps may rotateinto position without touching the substrate and hold the substrate inposition on the pedestal only if the substrate significantly lifts offthe pedestal during processing. With the pedestal rotating thesubstrate, a rinsing fluid is delivered onto the substrate front sidethrough the first fluid inlet 340. The second fluid, such as an acid, isdelivered to the backside surface through the second fluid inlet toremove any unwanted deposits. The dissolving fluid chemically reactswith the deposited material, dissolves, and then flushes the materialaway from the substrate backside and flushes the material away fromother areas that any unwanted deposits are located. In a preferredembodiment, the rinsing fluid is adjusted to flow at a greater rate thanthe dissolving fluid to help protect the front side of the substratefrom the dissolving fluid. The first and second fluid inlets are locatedfor optimal performance depending on the size of the substrate, therespective flow rates, spray patterns, and amount and type of depositsto be removed, among other factors. In some instances, the rinsing fluidcould be routed to the second fluid inlet after a dissolving fluid hasdissolved the unwanted deposits to rinse the backside of the substrate.In other instances, an auxiliary fluid inlet connected to flow rinsingfluid on the backside of the substrate could be used to rinse anydissolving fluid residue from the backside. After rinsing the front sideand/or backside of the substrate, the fluid(s) flow is stopped and thepedestal continues to rotate, spinning the substrate, and therebyeffectively drying the substrate surface.

The fluid(s) is generally delivered in a spray pattern, which may bevaried depending on the particular nozzle spray pattern desired and mayinclude a fan, jet, conical, and other patterns. One spray pattern forthe first and second fluids through the respective fluid inlets, whenthe first fluid is a rinsing fluid, is fan pattern with a pressure ofabout 10 to about 15 pounds per square inch (psi) and a flow rate ofabout 1 to about 3 gallons per minute (gpm) for, e.g., a 200 mmsubstrate.

The SRD module could also be used to remove the unwanted deposits alongthe edge of the substrate to create an edge exclusion zone. The unwanteddeposits could be removed from the edge and/or edge exclusion zone ofthe substrate by adjustment of the orientation and placement of thenozzles 348, 351, the flow rates of the fluids, the rotational speed ofthe substrate, and the chemical composition of the fluids. Thus,substantially preventing dissolution of the deposited material on thefront side surface may not necessarily include the edge or edgeexclusion zone of the substrate. Also, preventing dissolution of thedeposited material on the front side surface is intended to include atleast preventing the dissolution so that the front side with thedeposited material is not impaired beyond a commercial value.

One method of accomplishing the edge exclusion zone dissolution processis to rotate the disk at a slower speed, such as about 100 to about 1000rpm, while dispensing the dissolving fluid on the backside of thesubstrate. The inertia moves the dissolving fluid to the edge of thesubstrate and forms a layer of fluid around the edge due to surfacetension of the fluid, so that the dissolving fluid overlaps from thebackside to the front side in the edge area of the substrate. Therotational speed of the substrate and the flow rate of the dissolvingfluid may be used to determine the extent of the overlap onto the frontside. For instance, a decrease in rotational speed or an increase influid flow results in a less overlap of fluid to the opposing side,e.g., the front side. Additionally, the flow rate and flow angle of therinsing fluid delivered to the front side can be adjusted to offset thelayer of dissolving fluid onto the edge and/or frontside of thesubstrate. In some instances, the dissolving fluid may be used initiallywithout the rinsing fluid to obtain the edge and/or edge exclusion zoneremoval, followed by the rinsing/dissolving process of the SRD module.

The SRD module 236 is connected between the loading station 210 and themainframe 214. The mainframe 214 generally comprises a mainframetransfer station 216 and a plurality of processing stations 218.Referring to FIGS. 2 and 3, the mainframe 214, as shown, includes twoprocessing stations 218, each processing station 218 having two processcells 240. The mainframe transfer station 216 includes a mainframetransfer robot 242. Preferably, the mainframe transfer robot 242comprises a plurality of individual robot arms 244 that providesindependent access of substrates in the processing stations 218 and theSRD stations 212. As shown either in FIG. 2 or FIG. 3, the mainframetransfer robot 242 comprises two robot arms 244, corresponding to thenumber of process cells 240 per processing station 218. Each robot arm244 includes a robot blade 246 for holding a substrate during asubstrate transfer. Preferably, each robot arm 244 is operableindependently of the other arm to facilitate independent transfers ofsubstrates in the system. Alternatively, the robot arms 244 operate in acoordinated fashion such that one robot extends as the other robot armretracts.

Preferably, the mainframe transfer station 216 includes a flipper robot248 that facilitates transfer of a substrate from a face-up position onthe robot blade 246 of the mainframe transfer robot 242 to a face downposition for a process cell 240 that requires face-down processing ofsubstrates. The flipper robot 248 includes a main body 250 that providesboth vertical and rotational movements with respect to a vertical axisof the main body 250 and a flipper robot arm 252 that providesrotational movement along a horizontal axis along the flipper robot arm252. Preferably, a vacuum suction gripper 254, disposed at the distalend of the flipper robot arm 252, holds the substrate as the substrateis flipped and transferred by the flipper robot 248. The flipper robot248 positions a substrate 234 into the process cell 240 for face-downprocessing. The details of the electroplating process cell will bediscussed below.

FIG. 24 is a top schematic view of a mainframe transfer robot having aflipper robot incorporated therein. The mainframe transfer robot 242 asshown in FIG. 24 serves to transfer substrates between differentstations attached the mainframe station, including the processingstations and the SRD stations. The mainframe transfer robot 242 includesa plurality of robot arms 2402 (two are shown), and a flipper robot endeffector 2404 is attached as an end effector for each of the robot arms2402. Flipper robots are generally known in the art and can be attachedas end effectors for substrate handling robots, such as model RR701,available from Rorze Automation, Inc., located in Milpitas, Calif. Themain transfer robot 242 having a flipper robot as the end effector iscapable of transferring substrates between different stations attachedto the mainframe as well as flipping the substrate being transferred tothe desired surface orientation, i.e., substrate processing surfacebeing face-down for the electroplating process. Preferably, themainframe transfer robot 242 provides independent robot motion along theX-Y-Z axes by the robot arm 2402 and independent substrate flippingrotation by the flipper robot end effector 2404. By incorporating theflipper robot end effector 2404 as the end effector of the mainframetransfer robot 242, the substrate transfer process is simplified becausethe step of passing a substrate from a mainframe transfer robot to aflipper robot is eliminated.

FIG. 6 is a cross sectional view of an electroplating process cell 400.The electroplating process cell 400 as shown in FIG. 6 is the same asthe electroplating process cell 240 as shown in FIGS. 2 and 3. Theprocess cell 400 generally comprises a head assembly 410, a process cell420 and an electrolyte solution collector 440. Preferably, theelectrolyte solution collector 440 is secured onto the body 442 of themainframe 214 over an opening 443 that defines the location forplacement of the process cell 420. The electrolyte solution collector440 includes an inner wall 446, an outer wall 448 and a bottom 447connecting the walls. An electrolyte solution outlet 449 is disposedthrough the bottom 447 of the electrolyte solution collector 440 andconnected to the electrolyte solution replenishing system 220, shown inFIG. 2, through tubes, hoses, pipes or other fluid transfer connectors.

The head assembly 410 is mounted onto a head assembly frame 452. Thehead assembly frame 452 includes a mounting post 454 and a cantileverarm 456. The mounting post 454 is mounted onto the body 442 of themainframe 214, and the cantilever arm 456 extends laterally from anupper portion of the mounting post 454. Preferably, the mounting post454 provides rotational movement with respect to a vertical axis alongthe mounting post to allow rotation of the head assembly 410. The headassembly 410 is attached to a mounting plate 460 disposed at the distalend of the cantilever arm 456. The lower end of the cantilever arm 456is connected to a cantilever arm actuator 457, such as a pneumaticcylinder, mounted on the mounting post 454. The cantilever arm actuator457 provides pivotal movement of the cantilever arm 456 with respect tothe joint between the cantilever arm 456 and the mounting post 454. Whenthe cantilever arm actuator 457 is retracted, the cantilever arm 456moves the head assembly 410 away from the process cell 420 to providethe spacing required to remove and/or replace the process cell 420 fromthe electroplating process cell 400. When the cantilever arm actuator457 is extended, the cantilever arm 456 moves the head assembly 410toward the process cell 420 to position the substrate in the headassembly 410 in a processing position.

The head assembly 410 generally comprises a substrate holder assembly450 and a substrate assembly actuator 458. The substrate assemblyactuator 458 is mounted onto the mounting plate 460, and includes a headassembly shaft 462 extending downwardly through the mounting plate 460.The lower end of the head assembly shaft 462 is connected to thesubstrate holder assembly 450 to position the substrate holder assembly450 in a processing position and in a substrate loading position.

The substrate holder assembly 450 generally comprises a substrate holderelement 464 and a cathode contact ring 466. FIG. 7 is a cross sectionalview of one embodiment of a cathode contact ring 466. In general, thecontact ring 466 comprises an annular body having a plurality ofconducting members disposed thereon. The annular body is constructed ofan insulating material to electrically isolate the plurality ofconducting members. Together the body and conducting members form adiametrically interior substrate seating surface which, duringprocessing, supports a substrate and provides a current thereto.

Referring now to FIG. 7 in detail, the contact ring 466 generallycomprises a plurality of conducting members 765 at least partiallydisposed within an annular insulative body 770. The insulative body 770is shown having a flange 762 and a downward sloping shoulder portion 764leading to a substrate seating surface 768 located below the flange 762.The flange 762 and the substrate seating surface 768 lie in offset andsubstantially parallel planes. Thus, the flange 762 may be understood todefine a first plane while the substrate seating surface 768 defines asecond plane parallel to the first plane wherein the shoulder 764 isdisposed between the two planes. However, contact ring design shown inFIG. 7 is intended to be merely illustrative. In another embodiment, theshoulder portion 764 may be of a steeper angle including a substantiallyvertical angle so as to be substantially normal to both the flange 762and the substrate seating surface 768. Alternatively, the contact ring466 may be substantially planar thereby eliminating the shoulder portion764. However, for reasons described below, a preferred embodimentcomprises the shoulder portion 764 shown in FIG. 6 or some variationthereof.

The conducting members 765 are defined by a plurality of outerelectrical contact pads 780 annularly disposed on the flange 762, aplurality of inner electrical contact pads 772 disposed on a portion ofthe substrate seating surface 768, and a plurality of embeddedconducting connectors 776 which link the pads 772, 780 to one another.The conducting members 765 are isolated from one another by theinsulative body 770. The insulative body may be made of a plastic suchas polyvinylidenefluoride (PVDF), perfluoroalkoxy resin (PFA), Teflon™,and Tefzel™, or any other insulating material such as Alumina (Al₂O₃) orother ceramics. The outer contact pads 780 are coupled to a power supply(not shown) to deliver current and voltage to the inner contact pads 772via the connectors 776 during processing. In turn, the inner contactpads 772 supply the current and voltage to a substrate by maintainingcontact around a peripheral portion of the substrate. Thus, in operationthe conducting members 765 act as discrete current paths electricallyconnected to a substrate.

Low resistivity, and conversely high conductivity, are directly relatedto good plating. To ensure low resistivity, the conducting members 765are preferably made of copper (Cu), platinum (Pt), tantalum (Ta),titanium (Ti), gold (Au), silver (Ag), stainless steel or otherconducting materials. Low resistivity and low contact resistance mayalso be achieved by coating the conducting members 765 with a conductingmaterial. Thus, the conducting members 765 may, for example, be made ofcopper (resistivity for copper is approximately 2×10⁻⁸ Ω·m) and becoated with platinum (resistivity for platinum is approximately10.6×10⁻⁸ Ω·m). Coatings such as tantalum nitride (TaN), titaniumnitride (TiN), rhodium (Rh), Au, Cu, or Ag on a conductive basematerials such as stainless steel, molybdenum (Mo), Cu, and Ti are alsopossible. Further, since the contact pads 772, 780 are typicallyseparate units bonded to the conducting connectors 776, the contact pads772, 780 may comprise one material, such as Cu, and the conductingmembers 765 another, such as stainless steel. Either or both of the pads772, 180 and conducting connectors 776 may be coated with a conductingmaterial. Additionally, because plating repeatability may be adverselyaffected by oxidation that acts as an insulator, the inner contact pads772 preferably comprise a material resistant to oxidation such as Pt,Ag, or Au.

In addition to being a function of the contact material, the totalresistance of each circuit is dependent on the geometry, or shape, ofthe inner contact inner contact pads 772 and the force supplied by thecontact ring 466. These factors define a constriction resistance,R_(CR), at the interface of the inner contact pads 772 and the substrateseating surface 768 due to asperities between the two surfaces.Generally, as the applied force is increased the apparent area is alsoincreased. The apparent area is, in turn, inversely related to R_(CR) sothat an increase in the apparent area results in a decreased R_(CR).Thus, to minimize overall resistance it is preferable to maximize force.The maximum force applied in operation is limited by the yield strengthof a substrate that may be damaged under excessive force and resultingpressure. However, because pressure is related to both force and area,the maximum sustainable force is also dependent on the geometry of theinner contact pads 772. Thus, while the contact pads 772 may have a flatupper surface as in FIG. 7, other shapes may be used to advantage. Forexample, two preferred shapes are shown in FIGS. 8 and 9. FIG. 8 shows aknife-edge contact pad and FIG. 9 shows a hemispherical contact pad. Aperson skilled in the art will readily recognize other shapes which maybe used to advantage. A more complete discussion of the relation betweencontact geometry, force, and resistance is given in Ney Contact Manual,by Kenneth E. Pitney, The J. M. Ney Company, 1973, which is herebyincorporated by reference in its entirety.

The number of connectors 776 may be varied depending on the particularnumber of contact pads 772 desired, as shown in FIG. 7. For a 200 mmsubstrate, preferably at least twenty-four connectors 776 are spacedequally over 360°. However, as the number of connectors reaches acritical level, the compliance of the substrate relative to the contactring 466 is adversely affected. Therefore, while more than twenty-fourconnectors 776 may be used, contact uniformity may eventually diminishdepending on the topography of the contact pads 772 and the substratestiffness. Similarly, while less than twenty-four connectors 776 may beused, current flow is increasingly restricted and localized, leading topoor plating results. Since the dimensions are readily altered to suit aparticular application, for example a 300 mm substrate, the optimalnumber may easily be determined for varying scales and embodiments.

As shown in FIG. 10, the substrate seating surface 768 comprises anisolation gasket 782. The isolation gasket is disposed on the insulativebody 770 and extends diametrically interior to the inner contact pads772 to define the inner diameter of the contact ring 466. The isolationgasket 782 preferably extends slightly above the inner contact pads 772,e.g., a few mils, and preferably comprises an elastomer such as VITON®(a registered trademark of the E.I duPont de Nemoirs and Company ofWilmington, Del.), TEFLON®, buna rubber and the like. Where theinsulative body 770 also comprises an elastomer the isolation gasket 782may be of the same material, In the latter embodiment, the isolationgasket 782 and the insulative body 770 may be monolithic, ie., formed asa single piece. However, the isolation gasket 782 is preferably separatefrom the insulative body 770 so that it may be easily removed forreplacement or cleaning.

While FIG. 10 shows a preferred embodiment of the isolation gasket 782wherein the isolation gasket is seated entirely on the insulative body770, FIGS. 8 and 9 show an alternative embodiment. In the latterembodiment, the insulative body 770 is partially machined away to exposethe upper surface of the connecting member 776 and the isolation gasket782 is disposed thereon. Thus, the isolation gasket 782 contacts aportion of the connecting member 776. This design requires less materialto be used for he inner contact pads 772 that may be advantageous wherematerial costs are significant much as when the inner contact pads 772comprise gold.

During processing, the isolation gasket 782 maintains contact with aperipheral portion of the substrate plating surface and is compressed toprovide a seal between the remaining cathode contact ring 466 and thesubstrate. The seal prevents the electrolyte solution from contactingthe edge and backside of the substrate. As noted above, maintaining aclean contact surface is necessary to achieving high platingrepeatability. Previous contact ring designs did not provide consistentplating results because contact surface topography varied over time. Thecontact ring eliminates, or substantially minimizes, deposits that wouldotherwise accumulate on the inner contact pads 772 and change theircharacteristics thereby producing highly repeatable, consistent, anduniform plating across the substrate plating surface.

FIG. 11 is a simplified schematic diagram representing a possibleconfiguration of the electrical circuit for the contact ring 466. Toprovide a uniform current distribution between the conducting members765, an external resistor 700 is connected in series with each of theconducting members 765. Preferably, the resistance value of the externalresistor 700, represented as R_(EXT), is much greater than theresistance of any other component of the circuit. As shown in FIG. 11,the electrical circuit through each conducting member 765 is representedby the resistance of each of the components connected in series with thepower supply 702. R_(E) represents the resistance of the electrolytesolution, which is typically dependent on the distance between the anodeand the cathode contact ring and the chemical composition of theelectrolyte solution. Thus, R_(A) represents the resistance of theelectrolyte solution adjacent the substrate plating surface 754. R_(S)represents the resistance of the substrate plating surface 754, andR_(C) represents the resistance of the cathode conducting members 765plus the constriction resistance resulting at the interface between theinner contact pads 772 and the substrate plating layer 754. Generally,the resistance value of the external resistor (R_(EXT)) is at least asmuch as ΣR, where ΣR equals the sum of R_(E), R_(A), R_(S) and R_(C).Preferably, the resistance value of the external resistor, R_(EXT), ismuch greater than ΣR such that ΣR is negligible and the resistance ofeach series circuit approximates R_(EXT).

Typically, one power supply is connected to all of the outer contactpads 780 of the cathode contact ring 466, resulting in parallel circuitsthrough the inner contact pads 772. However, as the inner contactpad-to-substrate interface resistance varies with each inner contact pad772, more current will flow, and thus more plating will occur, at thesite of lowest resistance. However, by placing an external resistor inseries with each conducting member 765, the value or quantity ofelectrical current passed through each conducting member 765 becomescontrolled mainly by the value of the external resistor. As a result,the variations in the electrical properties between each of the innercontact pads 772 do not affect the current distribution on thesubstrate. The uniform current density applied across the platingsurface contributes to a uniform plating thickness of the metal filmdeposited on the seed layer on the substrate. The external resistorsalso provide a uniform current distribution between different substratesof a process-sequence.

Although the contact ring 466 is designed to resist deposit buildup onthe inner contact pads 772, over multiple substrate plating cycles thesubstrate-pad interface resistance may increase, eventually reaching anunacceptable value. An electronic sensor/alarm 704 can be connectedacross the external resistor 700 to monitor the voltage/current acrossthe external resistor to address this problem. If the voltage/currentacross the external resistor 700 falls outside of a preset operatingrange that is indicative of a high substrate-pad resistance, thesensor/alarm 704 triggers corrective measures such as shutting down theplating process until the problems are corrected by an operator.Alternatively, a separate power supply can be connected to eachconducting member 765 and can be separately controlled and monitored toprovide a uniform current distribution across the substrate. A verysmart system, VSS, may also be used to modulate the current flow. TheVSS typically comprises a processing unit and any combination of devicesknown in the industry used to supply and/or control current such asvariable resistors, separate power supplies, etc. As the physiochemical,and hence electrical, properties of the inner contact pads 772 changeover time, the VSS processes and analyzes data feedback. The data iscompared to pre-established setpoints and the VSS then makes appropriatecurrent and voltage alterations to ensure uniform deposition.

FIG. 18 is a perspective view of an alternative embodiment of a cathodecontact ring. The cathode contact ring 1800 as shown in FIG. 18comprises a conductive metal or a metal alloy, such as stainless steel,copper, silver, gold, platinum, titanium, tantalum, and other conductivematerials, or a combination of conductive materials, such as stainlesssteel coated with platinum. The cathode contact ring 1800 includes anupper mounting portion 1810 adapted for mounting the cathode contactring onto the substrate holder assembly and a lower substrate receivingportion 1820 adapted for receiving a substrate therein. The substratereceiving portion 1820 includes an annular substrate seating surface1822 having a plurality of contact pads or bumps 1824 disposed thereonand preferably evenly spaced apart. When a substrate is positioned onthe substrate seating surface 1822, the contact pads 1824 physicallycontact a peripheral region of the substrate to provide electricalcontact to the electroplating seed layer on the substrate depositionsurface. Preferably, the contact pads 1824 are coated with a noblemetal, such as platinum or gold, that is resistant to oxidation.

The exposed surfaces of the cathode contact ring, except the surfaces ofthe contact pads that come in contact with the substrate, are preferablytreated to provide hydrophilic surfaces or coated with a material thatexhibits hydrophilic properties. Hydrophilic materials and hydrophilicsurface treatments are known in the art. One company providing ahydrophilic surface treatment is Millipore Corporation, located inBedford, Mass. The hydrophilic surface significantly reduces beading ofthe electrolyte solution on the surfaces of the cathode contact ring andpromotes smooth dripping of the electrolyte solution from the cathodecontact ring after the cathode contact ring is removed from theelectroplating bath or electrolyte solution. By providing hydrophilicsurfaces on the cathode contact ring that facilitate run-off of theelectrolyte solution, plating defects caused by residual electrolytesolution on the cathode contact ring are significantly reduced. Theinventors also contemplate application of this hydrophilic treatment orcoating in other embodiments of cathode contact rings to reduce residualelectrolyte solution beading on the cathode contact ring and the platingdefects on a subsequently processed substrate that may result therefrom.

Referring to FIGS. 12 and 12A, the substrate holder element 464 ispreferably positioned above the cathode contact ring 466 and comprises abladder assembly 470 that provides pressure to the backside of asubstrate and ensures electrical contact between the substrate platingsurface and the cathode contact ring 466. The inflatable 110 bladderassembly 470 is disposed on a substrate holder plate 832. A bladder 836disposed on a lower surface of the substrate holder plate 832 is thuslocated opposite and adjacent to the contacts on the cathode contactring 466 with the substrate 821 interposed therebetween. A fluid source838 supplies a fluid, i.e., a gas or liquid, to the bladder 836 allowingthe bladder 836 to be inflated to varying degrees.

Referring now to FIGS. 12, 12A, and 13, the details of the bladderassembly 470 will be discussed. The substrate holder plate 832 is shownas substantially disc-shaped having an annular recess 840 formed on alower surface and a centrally disposed vacuum port 841. One or moreinlets 842 are formed in the substrate holder plate 832 and lead intothe relatively enlarged annular mounting channel 843 and the annularrecess 840. Quick-disconnect hoses 844 couple the fluid source 838 tothe inlets 842 to provide a fluid thereto. The vacuum port 841 ispreferably attached to a vacuum/pressure pumping system 859 adapted toselectively supply a pressure or create a vacuum at a backside of thesubstrate 821. The pumping system 859, shown in FIG. 12, comprises apump 845, a cross-over valve 847, and a vacuum ejector 849, commonlyknown as a venturi. One vacuum ejector is available from SMC Pneumatics,Inc., of Indianapolis, Ind. The pump 845 may be a commercially availablecompressed gas source and is coupled to one end of a hose 851, the otherend of the hose 851 being coupled to the vacuum port 841. The hose 851is split into a pressure line 853 and a vacuum line 855 having thevacuum ejector 849 disposed therein. Fluid flow is controlled by thecross-over valve 847 which selectively switches communication with thepump 845 between the pressure line 853 and the vacuum line 855.Preferably, the cross-over valve has an OFF setting whereby fluid isrestricted from flowing in either direction through hose 851. A shut-offvalve 861 disposed in hose 851 prevents fluid from flowing from pressureline 855 upstream through the vacuum ejector 849. The desired directionof fluid flow is indicated by arrows.

Where the fluid source 838 is a gas supply it may be coupled to hose 851thereby eliminating the need for a separate compressed gas supply, ie.,pump 845. Further, a separate gas supply and vacuum pump may supply thebackside pressure and vacuum conditions. While it is preferable to allowfor both a backside pressure as well as a backside vacuum, a simplifiedembodiment may comprise a pump capable of supplying only a backsidevacuum. However, as will be explained below, deposition uniformity maybe improved where a backside pressure is provided during processing.Therefore, an arrangement such as the one described above including avacuum ejector and a cross-over valve is preferred.

Referring now to FIGS. 12A and 14, a substantially circular ring-shapedmanifold 846 is disposed in the annular recess 840. The manifold 846comprises a mounting rail 852 disposed between an inner shoulder 848 andan outer shoulder 850. The mounting rail 852 is adapted to be at leastpartially inserted into the annular mounting channel 843. A plurality offluid outlets 854 formed in the manifold 846 provide communicationbetween the inlets 842 and the bladder 836. Seals 837, such as O-rings,are disposed in the annular manifold channel 843 in alignment with theinlet 842 and outlet 854 and secured by the substrate holder plate 832to ensure an airtight seal. Conventional fasteners such as screws may beused to secure the manifold 846 to the substrate holder plate 832 viacooperating threaded bores formed in the manifold 846 and the substrateholder plate 832.

Referring now to FIG. 15, the bladder 836 is shown, in section, as anelongated substantially semi-tubular piece of material having annularlip seals 856, or nodules, at each edge. In FIG. 12A, the lip seals 856are shown disposed on the inner shoulder 848 and the outer shoulder 850.A portion of the bladder 836 is compressed against the walls of theannular recess 840 by the manifold 846 which has a width slightly less,e.g. a few millimeters, than the annular recess 840. Thus, the manifold846, the bladder 836, and the annular recess 840 cooperate to form afluid-tight seal. To prevent fluid loss, the bladder 836 is preferablycomprised of some fluid impervious material such as silicon rubber orany comparable elastomer which is chemically inert with respect to theelectrolyte solution and exhibits reliable elasticity. Where needed acompliant covering 857 may be disposed over the bladder 836, as shown inFIG. 15, and secured by means of an adhesive or thermal bonding. Thecovering 857 preferably comprises an elastomer such as VITON® (aregistered trademark of the E.I. dupont de Nemoirs and Company ofWilmington, Del.), buna rubber or the like, which may be reinforced byKEVLAR® (a registered trademark of the E.I. dupont de Nemoirs andCompany of Wilmington, Del.), for example. In one embodiment, thecovering 857 and the bladder 836 comprise the same material. Thecovering 857 has particular application where the bladder 836 is liableto rupturing. Alternatively, the bladder 836 thickness may simply beincreased during its manufacturing to reduce the likelihood of puncture.Preferably, the exposed surface of the bladder 836, if uncovered, andthe exposed surface of the covering 857 are coated or treated to providea hydrophilic surface, as discussed above for the surfaces of thecathode contact ring. This coating promotes dripping and removal of theresidual electrolyte solution after the head assembly is lifted abovethe process cell.

The precise number of inlets 842 and outlets 854 may be varied accordingto the particular application. For example, while FIG. 12 shows twoinlets with corresponding outlets, an alternative embodiment couldemploy a single fluid inlet which supplies fluid to the bladder 836.

In operation, the substrate 821 is introduced into the container body802 by securing it to the lower side of the substrate holder plate 832.This is accomplished by engaging the pumping system 159 to evacuate thespace between the substrate 821 and the substrate holder plate 832 viaport 841 thereby creating a vacuum condition. The bladder 836 is theninflated by supplying a fluid such as air or water from the fluid source838 to the inlets 842. The fluid is delivered into the bladder 836 viathe manifold outlets 854, thereby pressing the substrate 821 uniformlyagainst the contacts of the cathode contact ring 466. The electroplatingprocess is then carried out. Electrolyte solution is then pumped intothe process cell 420 toward the substrate 821 to contact the exposedsubstrate plating surface 820. The power supply provides a negative biasto the substrate plating surface 820 via the cathode contact ring 466.As the electrolyte solution is flowed across the substrate platingsurface 820, ions in the electrolytic solution are attracted to thesurface 820 and deposit on the surface 820 to form the desired film.

Because of its flexibility, the bladder 836 deforms to accommodate theasperities of the substrate backside and contacts of the cathode contactring 466 thereby mitigating misalignment with the conducting cathodecontact ring 466. The compliant bladder 836 prevents the electrolytesolution from contaminating the backside of the substrate 821 byestablishing a fluid tight seal at a perimeter portion of a backside ofthe substrate 821. Once inflated, a uniform pressure is delivereddownward toward the cathode contact ring 466 to achieve substantiallyequal force at all points where the substrate 821 and cathode contactring 466 interface. The force can be varied as a function of thepressure supplied by the fluid source 838. Further, the effectiveness ofthe bladder assembly 470 is not dependent on the configuration of thecathode contact ring 466. For example, while FIG. 12 shows a pinconfiguration having a plurality of discrete contact points, the cathodecontact ring 466 may also be a continuous surface.

Because the force delivered to the substrate 821 by the bladder 836 isvariable, adjustments can be made to the current flow supplied by thecontact ring 466. As described above, an oxide layer may form on thecathode contact ring 466 and act to restrict current flow. However,increasing the pressure of the bladder 836 may counteract the currentflow restriction due to oxidation. As the pressure is increased, themalleable oxide layer is compromised and superior contact between thecathode contact ring 466 and the substrate 821 results. Theeffectiveness of the bladder 836 in this capacity may be furtherimproved by altering the geometry of the cathode contact ring 466. Forexample, a knife-edge geometry is likely to penetrate the oxide layermore easily than a dull rounded edge or flat edge.

Additionally, the fluid tight seal provided by the inflated bladder 836allows the pump 845 to maintain a backside vacuum or pressure eitherselectively or continuously, before, during, and after processing.Generally, however, the pump 858 is run only during the transfer ofsubstrates to and from the electroplating process cell 400 because thebladder 836 is capable of maintaining the backside vacuum conditionduring processing without continuous pumping. Thus, while inflating thebladder 836, as described above, the backside vacuum condition issimultaneously relieved by disengaging the pumping system 859, e.g., byselecting an OFF position on the crossover valve 847. Disengaging thepumping system 859 may be abrupt or comprise a gradual process wherebythe vacuum condition is ramped down. Ramping allows for a controlledexchange between the inflating bladder 836 and the simultaneouslydecreasing backside vacuum condition. This exchange may be controlledmanually or by computer.

As described above, continuous backside vacuum pumping while the bladder836 is inflated is not needed and may actually cause the substrate 820to buckle or warp leading to undesirable deposition results. It may bedesirable to provide a backside pressure to the substrate 820 in orderto cause a “bowing” effect of the substrate to be processed. Bowing ofthe substrate may result in superior deposition. Thus, pumping system859 is capable of selectively providing a vacuum or pressure conditionto the substrate backside. For a 200 mm substrate a backside pressure upto 5 psi is preferable to bow the substrate. Because substratestypically exhibit some measure of pliability, a backside pressure causesthe substrate to bow or assume a convex shape relative to the upwardflow of the electrolyte solution. The degree of bowing is variableaccording to the pressure supplied by pumping system 859.

While FIG. 12A shows a preferred bladder 836 having a surface areasufficient to cover a relatively small perimeter portion of thesubstrate backside at a diameter substantially equal to the cathodecontact ring 466. The geometric configuration of the bladder assembly470 can be varied. Thus, the bladder assembly may be constructed usingmore fluid impervious material to cover an increased surface area of thesubstrate 821.

FIG. 19 is a partial cross sectional view of an alternative embodimentof a substrate holder assembly. The alternative substrate holderassembly 1900 comprises a bladder assembly 470, as described above,having the inflatable bladder 836 attached to the back surface of anintermediary substrate holder plate 1910. Preferably, a portion of theinflatable bladder 836 is sealingly attached to the back surface 1912 ofthe intermediary substrate holder plate 1910 using an adhesive or otherbonding material. The front surface 1914 of the intermediary substrateholder plate 1910 is adapted to receive a substrate 821 to be processed.An elastomeric o-ring 1916 is disposed in an annular groove 1918 on thefront surface 1914 of the intermediary substrate holder plate 1910 tocontact a peripheral portion of the substrate back surface. Theelastomeric O-ring 1916 provides a seal between the substrate backsurface and the front surface of the intermediary substrate holderplate. Preferably, the intermediary substrate holder plate includes aplurality of bores or holes 1920 extending through the plate that are influid communication with the vacuum port 841. The plurality of holds1920 facilitate securing the substrate on the substrate holder elementusing a vacuum force applied to the backside of the substrate. Accordingto this alternative embodiment of the substrate holder assembly, theinflatable bladder does not directly contact a substrate beingprocessed, and thus the risk of cutting or damaging the inflatablebladder during substrate transfers is significantly reduced. Theelastomeric O-ring 1916 is preferably coated or treated to provide ahydrophilic surface, as discussed above for the surfaces of the cathodecontact ring, for contacting the substrate. The elastomeric O-ring 1916is replaced as needed to ensure proper contact and seal to thesubstrate.

FIG. 25 is an alternative embodiment of the process head assembly havinga rotatable head assembly 2410. Preferably, a rotational actuator isdisposed on the cantilevered arm and attached to the head assembly torotate the head assembly during substrate processing. The rotatable headassembly 2410 is mounted onto a head assembly frame 2452. Thealternative head assembly frame 2452 and the rotatable head assembly2410 are mounted onto the mainframe similarly to the head assembly frame452 and head assembly 410 as shown in FIG. 6 and described above. Thehead assembly frame 2452 includes a mounting post 2454, a post cover2455, and a cantilever arm 2456. The mounting post 2454 is mounted ontothe body of the mainframe 214, and the post cover 2455 covers a topportion of the mounting post 2454. Preferably, the mounting post 454provides rotational movement, as indicated by arrow Al, with respect toa vertical axis along the mounting post to allow rotation of the headassembly frame 2452. The cantilever arm 2456 extends laterally from anupper portion of the mounting post 2454 and is pivotally connected tothe post cover 2455 at the pivot joint 2459. The rotatable head assembly2410 is attached to a mounting slide 2460 disposed at the distal end ofthe cantilever arm 2456. The mounting slide 2460 guides the verticalmotion of the head assembly 2410. A head lift actuator 2458 is disposedon top of the mounting slide 2460 to provide vertical displacement ofthe head assembly 2410.

The lower end of the cantilever arm 2456 is connected to the shaft 2453of a cantilever arm actuator 2457, such as a pneumatic cylinder or alead-screw actuator, mounted on the mounting post 2454. The cantileverarm actuator 2457 provides pivotal movement, as indicated by arrow A2,of the cantilever arm 2456 with respect to the joint 2459 between thecantilever arm 2456 and the post cover 2454. When the cantilever armactuator 2457 is retracted, the cantilever arm 2456 moves the headassembly 2410 away from the process cell 420. The movement of the headassembly 2410 provides the spacing required to remove and/or replace theprocess cell 420 from the electroplating process cell 240. When thecantilever arm actuator 2457 is extended, the cantilever arm 2456 movesthe head assembly 2410 toward the process cell 420 to position thesubstrate in the head assembly 2410 in a processing position.

The rotatable head assembly 2410 includes a rotating actuator 2464slideably connected to the mounting slide 2460. The shaft 2468 of thehead lift actuator 2458 is inserted through a lift guide 2466 attachedto the body of the rotating actuator 2464. Preferably, the shaft 2468 isa lead-screw type shaft that moves the lift guide, as indicated byarrows A3, between various vertical positions. The rotating actuator2464 is connected to the substrate bolder assembly 2450 through theshaft 2470 and rotates the substrate holder assembly 2450, as indicatedby arrows A4. The substrate holder assembly 2450 includes a bladderassembly, such as the embodiments described above with respect to FIGS.12-15 and 19, and a cathode contact ring, such as the embodimentsdescribed above with respect to FIGS. 7-10 and 18.

The rotation of the substrate during the electroplating processgenerally enhances the deposition results. Preferably, the head assemblyis rotated between about 2 rpm and about 20 rpm during theelectroplating process. The head assembly can also be rotated. The headassembly can be lowered to position the seed layer on the substrate incontact with the electrolyte solution in the process cell. The headassembly is raised to remove the seed layer on the substrate from theelectrolyte solution in the process cell. The head assembly ispreferably rotated at a high speed, i.e., > about 20 rpm, after the headassembly is lifted from the process cell to enhance removal of residualelectrolyte solution on the head assembly.

In one embodiment, the uniformity of the deposited film has beenimproved within about 2%, i.e., maximum deviation of deposited filmthickness is at about 2% of the average film thickness, while standardelectroplating processes typically achieves uniformity at best withinabout 5.5%. However, rotation of the head assembly is not necessary toachieve uniform electroplating deposition in some instances,particularly where the uniformity of electroplating deposition isachieved by adjusting the processing parameters, such as the chemicalsin the electrolyte solution, electrolyte solution flow and otherparameters.

Referring back to FIG. 6, a cross sectional view of an electroplatingprocess cell 400, the substrate holder assembly 450 is positioned abovethe process cell 420. The process cell 420 generally comprises a bowl430, a container body 472, an anode assembly 474 and a filter 476.Preferably, the anode assembly 474 is disposed below the container body472 and attached to a lower portion of the container body 472, and thefilter 476 is disposed between the anode assembly 474 and the containerbody 472. The container body 472 is preferably a cylindrical bodycomprised of an electrically insulative material, such as ceramics,plastics, PLEXIGLAS® (acrylic), lexane, PVC, CPVC, and PVDF.Alternatively, the container body 472 ran be made from a coated metal,such as stainless steel, nickel and titanium. The coated metal is coatedwith an insulating layer such as TEFLON® (a trademark of E. I. du Pontde Nemours and Company, Wilmington, Del.), PVDF, plastic, rubber andother combinations of materials) that do not dissolve in the electrolytesolution. The insulating layer can be electrically insulated from theelectrodes, i.e., the anode and cathode of the electroplating system.The container body 472 is preferably sized and adapted to conform to thesubstrate plating surface and the shape of the of a substrate beingprocessed through the system, typically circular or rectangular. Onepreferred embodiment of the container body 472 comprises a cylindricalceramic tube having an inner diameter that has about the same dimensionas or slightly larger than the substrate diameter. The inventors havediscovered that the rotational movement typically required in typicalelectroplating systems is not required to achieve uniform platingresults when the size of the container body conforms to about the sizeof the substrate plating surface.

An upper portion of the container body 472 extends radially outwardly toform an annular weir 478. The weir 478 extends over the inner wall 446of the electrolyte solution collector 440 and allows the electrolytesolution to flow into the electrolyte solution collector 440. The uppersurface of the weir 478 preferably matches the lower surface of thecathode contact ring 466. Preferably, the upper surface of the weir 478includes an inner annular flat portion 480, a middle inclined portion482 and an outer declined portion 484. When a substrate is positioned inthe processing position, the substrate plating surface is positionedabove the cylindrical opening of the container body 472. A gap forelectrolyte solution flow is formed between the lower surface of thecathode contact ring 466 and the upper surface of the weir 478. Thelower surface of the cathode contact ring 466 is disposed above theinner flat portion 480 and the middle inclined portion of the weir 478.The outer declined portion 484 is sloped downwardly to facilitate flowof the electrolyte solution into the electrolyte solution collector 440.

A lower portion of the container body 472 extends radially outwardly toform a lower annular flange 486 for securing the container body 472 tothe bowl 430. The outer dimension, ie., circumference, of the annularflange 486 is smaller than the dimensions of the opening 444 and theinner circumference of the electrolyte solution collector 440. Thesmaller dimension of the annular flange to allow removal and replacementof the process cell 420 from the electroplating process cell 400.Preferably, multiple bolts 488 are fixedly disposed on the annularflange 486 and extend downwardly through matching bolt holes on the bowl430. A plurality of removable fastener nuts 490 secure the process cell420 onto the bowl 430. A seal 487, such as an elastomer O-ring, isdisposed between container body 472 and the bowl 430 radially inwardlyfrom the bolts 488 to prevent leaks from the process cell 420. Thenuts/bolts combination facilitates fast and easy removal and replacementof the components of the process cell 420 during maintenance.

Preferably, the filter 476 is attached to and completely covers thelower opening of the container body 472, and the anode assembly 474 isdisposed below the filter 476. A spacer 492 is disposed between thefilter 476 and the anode assembly 474. Preferably, the filter 476, thespacer 492, and the anode assembly 474 are fastened to a lower surfaceof the container body 472 using removable fasteners, such as screwsand/or bolts. Alternatively, the filter 476, the spacer 492, and theanode assembly 474 are removably secured to the bowl 430.

The anode assembly 474 preferably comprises a consumable anode thatserves as a metal source in the electrolyte solution. Alternatively, theanode assembly 474 comprises a non-consumable anode, and the metal to beelectroplated is supplied within the electrolyte solution from theelectrolyte solution replenishing system 220. As shown in FIG. 6, theanode assembly 474 is a self-enclosed module having a porous anodeenclosure 494 preferably made of the same metal as the metal to beelectroplated, such as copper. Alternatively, the anode enclosure 494 ismade of porous materials, such as ceramics or polymeric membranes. Asoluble metal 496, such as high purity copper for electro-chemicaldeposition of copper, is disposed within the anode enclosure 494. Thesoluble metal 496 preferably comprises metal particles, wires or aperforated sheet. The porous anode enclosure 494 also acts as a filterthat keeps the particulates generated by the dissolving metal within theanode enclosure 494. As compared to a non-consumable anode, theconsumable, i.e., soluble, anode provides gas-generation-freeelectrolyte solution and minimizes the need to constantly replenish themetal in the electrolyte solution.

An anode electrode contact 498 is inserted through the anode enclosure494 to provide electrical connection to the soluble metal 496 from apower supply. Preferably, the anode electrode contact 498 is made from aconductive material that is insoluble in the electrolyte solution, suchas titanium, platinum and platinum-coated stainless steel. The anodeelectrode contact 498 extends through the bowl 430 and is connected toan electrical power supply. Preferably, the anode electrical contact 498includes a threaded portion 497 for a fastener nut 499 to secure theanode electrical contact 498 to the bowl 430, and a seal 495 such as aelastomer washer. The seal 495 is disposed between the fastener nut 499and the bowl 430 to prevent leaks from the process cell 420.

The bowl 430 generally comprises a cylindrical portion 502 and a bottomportion 504. An upper annular flange 506 extends radially outwardly fromthe top of the cylindrical portion 502. The upper annular flange 506includes a plurality of holes 508 that matches the number of bolts 488from the lower annular flange 486 of the container body 472. Bolts 488are inserted through the holes 508, and the fastener nuts 490 arefastened onto the bolts 488 that secure the upper annular flange 506 ofthe bowl 430 to the lower annular flange 486 of the container body 472.Preferably, the outer dimension, i.e., circumference, of the upperannular flange 506 is about the same as the outer dimension, ie.,circumference, of the lower annular flange 486. Preferably, the lowersurface of the upper annular flange 506 of the bowl 430 rests on asupport flange of the mainframe 214 when the process cell 420 ispositioned on the mainframe 214.

The inner circumference of the cylindrical portion 502 accommodates theanode assembly 474 and the filter 476. Preferably, the outer dimensionsof the filter 476 and the anode assembly 474 are slightly smaller thanthe inner dimension of the cylindrical portion 502. These relativedimensions force a substantial portion of the electrolyte solution toflow through the anode assembly 474 first before flowing through thefilter 476. The bottom portion 504 of the bowl 430 includes anelectrolyte solution inlet 510 that connects to an electrolyte solutionsupply line from the electrolyte solution replenishing system 220.Preferably, the anode assembly 474 is disposed about a middle portion ofthe cylindrical portion 502 of the bowl 430. The anode assembly 474 isconfigured to provide a gap for electrolyte solution flow between theanode assembly 474 and the electrolyte solution inlet 510 on the bottomportion 504.

The electrolyte solution inlet 510 and the electrolyte solution supplyline are preferably connected by a releasable connector that facilitateseasy removal and replacement of the process cell 420. When the processcell 420 needs maintenance, the electrolyte solution is drained from theprocess cell 420, and the electrolyte solution flow in the electrolytesolution supply line is discontinued and drained. The connector for theelectrolyte solution supply line is released from the electrolytesolution inlet 510, and the electrical connection to the anode assembly474 is also disconnected. The head assembly 410 is raised or rotated toprovide clearance for removal of the process cell 420. The process cell420 is then removed from the mainframe 214, and a new or reconditionedprocess cell is replaced into the mainframe 214.

Alternatively, the bowl 430 can be secured onto the support flange ofthe mainframe 214, and the container body 472 along with the anode andthe filter are removed for maintenance. In this case, the nuts securingthe anode assembly 474 and the container body 472 to the bowl 430 areremoved to facilitate removal of the anode assembly 474 and thecontainer body 472. New or reconditioned anode assembly 474 andcontainer body 472 are then replaced into the mainframe 214 and securedto the bowl 430.

FIG. 20 is a cross sectional view of one embodiment of an encapsulatedanode. The encapsulated anode 2000 includes a permeable anode enclosurethat filters or traps “anode sludge” or particulates generated as themetal is dissolved from the anode plate 2004. As shown in FIG. 20, theanode plate 2004 comprises a solid piece of copper. Preferably, theanode plate 2004 is a high purity, oxygen free copper, enclosed in ahydrophilic anode encapsulation membrane 2002. The anode plate 2004 issecured and supported by a plurality of electrical contacts orfeed-throughs 2006 that extend through the bottom of the bowl 430. Theelectrical contacts or feed-throughs 2006 extend through the anodeencapsulation membrane 2002 into the bottom surface of the anode plate2004. The flow of the electrolyte solution is indicated by the arrows Afrom the electrolyte solution inlet 510 disposed at the the bottom ofthe bowl 430 through the gap between the anode and the bowl sidewall.The electrolyte solution also flows through the anode encapsulationmembrane 2002 by permeation into and out of the gap between the anodeencapsulation membrane and the anode plate, as indicated by the arrowsB. Preferably, the anode encapsulation membrane 2002 comprises ahydrophilic porous membrane, such as a modified polyvinyllidene fluoridemembrane, having porosity between about 60% and 80%, more preferablyabout 70%, and pore sizes between about 0.025 μm and about 1 μm, morepreferably between about 0.1 μm and about 0.2 μm. One example of ahydrophilic porous membrane is the Durapore Hydrophilic Membrane,available from Millipore Corporation, located in Bedford, Mass. As theelectrolyte solution flows through the encapsulation membrane, anodesludge and particulates generated by the dissolving anode are filteredor trapped by the encapsulation membrane. Thus, the encapsulationmembranes improve the purity of the electrolyte solution during theelectroplating process, and defect formations on the substrate duringthe electroplating process caused by anode sludge and contaminantparticulates are significantly reduced.

FIG. 21 is a cross sectional view of another embodiment of anencapsulated anode. The anode plate 2004 is secured and supported on theelectrical feed-throughs 2006. A top encapsulation membrane 2008 and abottom encapsulation membrane 2010 are disposed respectively above andbelow the anode plate 2004, are attached to a membrane support ring 2012that is disposed around the anode plate 2004. The top and bottomencapsulation membranes 2008, 2010 comprise a material from the listabove for encapsulation membrane of the first embodiment of theencapsulated anode. The membrane support ring 2012 preferably comprisesa relatively rigid material as compared to the encapsulation membrane,such as plastic or other polymers. A bypass fluid inlet 2014 is disposedthrough the bottom of the bowl 430 and through the bottom encapsulationmembrane 2010 to introduce electrolyte solution into the gap between theencapsulation membranes and the anode plate. A bypass outlet 2016 isconnected to the membrane support ring 2012 and extends through the bowl430 to facilitate flow of excess electrolyte solution with the anodesludge or generated particulates out of the encapsulated anode into awaste drain, not shown.

Preferably, the flow of the electrolyte solution within the bypass fluidinlet 2014 and the main electrolyte solution inlet 510 are individuallycontrolled by flow control valves 2020, 2022. The individual flowcontrol valves 2020, 2022 are respectively placed along the fluid linesconnected to the inlets. The fluid pressure in the bypass fluid inlet2014 is preferably maintained at a higher pressure than the pressure inthe main electrolyte solution inlet 510. The flow of the electrolytesolution inside the bowl 430 from the main electrolyte solution inlet510 is indicated by arrows A, and the flow of the electrolyte solutioninside the encapsulated anode 2000 is indicated by the arrows B. Aportion of the electrolyte solution introduced into the encapsulatedanode flows out of the encapsulated anode through the bypass outlet2016. By providing a dedicated bypass electrolyte solution supply intothe encapsulated anode, the anode sludge or particulates generated fromthe dissolving anode is continually removed from the anode, therebyimproving the purity of the electrolyte solution during theelectroplating process.

FIG. 22 is a cross sectional view of another embodiment of anencapsulated anode. This embodiment of an encapsulated anode 2000includes an anode plate 2002, a top encapsulation membrane 2006, abottom encapsulation membrane 2010, and a membrane support ring 2012.The anode plate 2002 is secured and supported on a plurality ofelectrical feed-throughs 2006. A top and a bottom encapsulation membrane2008, 2010 are attached to a membrane support ring 2012. A bypass fluidinlet 2014 is disposed through the bottom of the bowl 430 and throughthe bottom encapsulation membrane 2010 to introduce electrolyte solutioninto the gap between the encapsulation membranes and the anode plate.This third embodiment of an encapsulated anode preferably comprisesmaterials as described above for the first and second embodiments of anencapsulated anode. The bottom encapsulation membrane 2010 according tothe third embodiment includes one or more openings 2024 disposedsubstantially above the main electrolyte solution inlet 510. The opening2024 is adapted to receive flow of electrolyte solution from the mainelectrolyte solution inlet 510 and is preferably about the same size asthe internal circumference of the main electrolyte solution inlet 510.The flow of the electrolyte solution from the main electrolyte solutioninlet 510 is indicated by the arrows A and the flow of the electrolytesolution within the encapsulated anode is indicated by the arrows B. Aportion of the electrolyte solution flows out of the encapsulated anodethrough the bypass outlet 2016, carrying a portion of the anode sludgeand particulates generated from anode dissolution.

FIG. 23 is a cross sectional view of yet another embodiment of anencapsulated anode. This embodiment of an encapsulated anode 2000includes an anode plate 2002, a top encapsulation membrane 2006, abottom encapsulation membrane 2010, and a membrane support ring 2012.The anode plate 2002 is secured and supported on a plurality ofelectrical feed-throughs 2006. A top and a bottom encapsulation membrane2008, 2010 are attached to a membrane support ring 2012. A bypass fluidinlet 2014 is disposed through the bottom of the bowl 430 and throughthe bottom encapsulation membrane 2010 to introduce electrolyte solutioninto the gap between the encapsulation membranes and the anode plate.This embodiment of an encapsulated anode preferably comprises materialsas described above for the first and second embodiments of anencapsulated anode. Preferably, the flow of the electrolyte solutionthrough the bypass fluid inlet 2014 and the main electrolyte solutioninlet 510 are individually controlled by control valves 2020, 2022,respectively. The flow of the electrolyte solution from the mainelectrolyte solution inlet 510 is indicated by the arrows A while theflow of the electrolyte solution through the encapsulated anode isindicated by arrows B. For this embodiment, the anode sludge andparticulates generated by the dissolving anode plate are filtered andtrapped by the encapsulation membranes as the electrolyte solutionpasses through the membrane.

FIG. 16 is a schematic diagram of an electrolyte solution replenishingsystem 220. The electrolyte solution replenishing system 220 providesthe electrolyte solution to the electroplating process cells for theelectroplating process. The electrolyte solution replenishing system 220generally comprises a main electrolyte solution tank 602, a dosingmodule 603, a filtration module 605, a chemical analyzer module 616, andan electrolyte solution waste disposal system 622 connected to theanalyzing module 616 by an electrolyte solution waste drain 620. One ormore controllers control the composition of the electrolyte solution inthe main tank 602 and the operation of the electrolyte solutionreplenishing system 220. Preferably, the controllers are independentlyoperable but integrated with the controller 222 of the electroplatingsystem platform 200.

The main electrolyte solution tank 602 provides a reservoir forelectrolyte solution and includes an electrolyte solution supply line612 that is connected to each of the electroplating process cellsthrough one or more fluid pumps 608 and valves 607. A heat exchanger 624or a heater/chiller disposed in thermal connection with the main tank602 controls the temperature of the electrolyte solution stored in themain tank 602. The heat exchanger 624 is connected to and operated bythe controller 610.

The dosing module 603 is connected to the main tank 602 by a supply lineand includes a plurality of source tanks 606, or feed bottles, aplurality of valves 609, and a controller 611. The source tanks 606contain the chemicals needed for composing the electrolyte solution andtypically include a deionized water source tank and copper sulfate(CuSO₄) source tank for composing the electrolyte solution. Other sourcetanks 606 may contain hydrogen sulfate (H₂SO₄), hydrogen chloride (HCl)and various additives such as glycol. Each source tank is preferablycolor coded and fitted with a unique mating outlet connector adapted toconnect to a matching inlet connector in the dosing module. By colorcoding the source tanks and fitting the source tanks with uniqueconnectors, errors caused by human operators when exchanging orreplacing the source tanks are significantly reduced.

The deionized water source tank preferably also provides deionized waterto the system for cleaning the system during maintenance. The valves 609associated with each source tank 606 regulate the flow of chemicals tothe main tank 602 and may be any of numerous commercially availablevalves such as butterfly valves, throttle valves and the like.Activation of the valves 609 is accomplished by the controller 611 whichis preferably connected to the system control 222 to receive signalstherefrom.

The electrolyte solution filtration module 605 includes a plurality offilter tanks 604. An electrolyte solution return line 614 is connectedbetween each of the process cells and one or more filter tanks 604. Thefilter tanks 604 remove the undesired contents in the used electrolytesolution before returning the electrolyte solution to the main tank 602for re-use. The main tank 602 is also connected to the filter tanks 604to facilitate recirculation and filtration of the electrolyte solutionin the main tank 602. By re-circulating the electrolyte solution fromthe main tank 602 through the filter tanks 604, the undesired contentsin the electrolyte solution are continuously removed by the filter tanks604 to maintain a consistent level of purity. Additionally,recirculating the electrolyte solution between the main tank 602 and thefiltration module 605 allows the various chemicals in the electrolytesolution to be thoroughly mixed.

The electrolyte solution replenishing system 220 also includes achemical analyzer module 616 that provides real-time chemical analysisof the chemical composition of the electrolyte solution. The analyzermodule 616 is fluidly coupled to the main tank 602 by a sample line 613and to the waste disposal system 622 by an outlet line 621. The analyzermodule 616 generally comprises at least one analyzer and a controller tooperate the analyzer. The number of analyzers required for a particularprocessing tool depends on the composition of the electrolyte solution.For example, while a first analyzer may be used to monitor theconcentrations of organic substances, a second analyzer is needed forinorganic chemicals. In the specific embodiment shown in FIG. 16 thechemical analyzer module 616 comprises an auto titration analyzer 615and a cyclic voltametric stripper (CVS) 617. Both analyzers arecommercially available from various suppliers. An auto titrationanalyzer which may be used to advantage is available from Parker Systemsand a cyclic voltametric stripper is available from ECI. The autotitration analyzer 615 determines the concentrations of inorganicsubstances such as copper chloride and acid. The CVS 617 determines theconcentrations of organic substances such as the various additives whichmay be used in the electrolyte solution and by-products resulting fromthe processing which are returned to the main tank 602 from the processcells.

The analyzer module shown FIG. 16 is merely illustrative. In anotherembodiment each analyzer may be coupled to the main electrolyte solutiontank by a separate supply line and be operated by separate controllers.Persons skilled in the art will recognize other embodiments.

In operation, a sample of electrolyte solution is flowed to the analyzermodule 616 via the sample line 613. Although the sample may be takenperiodically, preferably a continuous flow of electrolyte solution ismaintained to the analyzer module 616. A portion of the sample isdelivered to the auto titration analyzer 615 and a portion is deliveredto the CVS 617 for the appropriate analysis. The controller 619initiates command signals to operate the analyzers 615, 617 in order togenerate data. The information from the chemical analyzers 615, 617 isthen communicated to the controller 222. The controller 222 processesthe information and transmits signals that include user-defined chemicaldosage parameters to the dosing controller 611. The received informationis used to provide real-time adjustments to the source chemicalreplenishment rates by operating one or more of the valves 609. Thereceived information thereby maintains a desired, and preferablyconstant, chemical composition of the electrolyte solution throughoutthe electroplating process. The waste electrolyte solution from theanalyzer module is then flowed to the waste disposal system 622 via theoutlet line 621.

Although a preferred embodiment utilizes real-time monitoring andadjustments of the electrolyte solution, various alternatives may beemployed. For example, the dosing module 603 may be controlled manuallyby an operator observing the output values provided by the chemicalanalyzer module 616. Preferably, the system software allows for both anautomatic real-time adjustment mode as well as an operator (manual)mode. Further, although multiple controllers are shown in FIG. 16, asingle controller may be used to operate various components of thesystem such as the chemical analyzer module 616, the dosing module 603,and the heat exchanger 624. Other embodiments will be apparent to thoseskilled in the art.

The electrolyte solution replenishing system 220 also includes anelectrolyte solution waste drain 620 connected to an electrolytesolution waste disposal system 622 for safe disposal of used electrolytesolutions, chemicals and other fluids used in the electroplating system.Preferably, the electroplating cells include a direct line connection tothe electrolyte solution waste drain 620 or the electrolyte solutionwaste disposal system 622. The electrolyte solution waste drain 620drains the electroplating cells without returning the electrolytesolution through the electrolyte solution replenishing system 220. Theelectrolyte solution replenishing system 220 preferably also includes ableed off connection to bleed off excess electrolyte solution to theelectrolyte solution waste drain 620.

Preferably, the electrolyte solution replenishing system 220 alsoincludes one or more degasser modules 630 adapted to remove undesirablegases from the electrolyte solution. The degasser module generallycomprises a membrane that separates gases from the fluid passing throughthe degasser module and a vacuum system for removing the released gases.The degasser modules 630 are preferably placed in line on theelectrolyte solution supply line 612 adjacent to the process cells 240.The degasser modules 630 are preferably positioned as close as possibleto the process cells 240 so most of the gases from the electrolytesolution replenishing system are removed by the degasser modules beforethe electrolyte solution enters the process cells. Preferably, eachdegasser module 630 includes two outlets to supply degassed electrolytesolution to the two process cells 240 of each processing station 218.Alternatively, a degasser module 630 is provided for each process cell.The degasser modules can be placed at many other alternative positions.For example, the degasser module can be placed at other positions in theelectrolyte solution replenishing system, such as along with the filtersection or in a closed-loop system with the main tank or with theprocess cell. As another example, one degasser module is placed in linewith the electrolyte solution supply line 612 to provide degassedelectrolyte solution to all of the process cells 240 of theelectro-chemical deposition system. Additionally, a separate degassermodule is positioned in-line or in a closed-loop with the deionizedwater supply line and is dedicated for removing oxygen from thedeionized water source. Because deionized water is used to rinse theprocessed substrates, free oxygen gases are preferable removed from thedeionized water before reaching the SRD modules so that theelectroplated copper is less likely to become oxidized by the rinsingprocess. Degasser modules are well known in the art and commercialembodiments are generally available and adaptable for use in a varietyof applications. A commercially available degasser module is availablefrom Millipore Corporation, located in Bedford, Mass.

One embodiment of the degasser module 630, as shown in FIG. 26 a,includes a hydrophobic membrane 632 having a fluid, ie., electrolytesolution, passage 634 on one side of the membrane 632. A vacuum system636 disposed on the opposite side of the membrane. The enclosure 638 ofthe degasser module includes an inlet 640 and one or more outlets 642.As the electrolyte solution passes through the degasser module 630, thegases and other micro-bubbles in the electrolyte solution are separatedfrom the electrolyte solution through the hydrophobic membrane andremoved by the vacuum system. Another embodiment of the degasser module630′, as shown in FIG. 26 b, includes a tube of hydrophobic membrane632′ and a vacuum system 636 disposed around the tube of hydrophobicmembrane 632′. The electrolyte solution is introduced inside the tube ofhydrophobic membrane, and as the electrolyte solution passes through thefluid passage 634 in the tube. The hydrophobic membrane separates gasesand other micro-bubbles in the electrolyte solution, and a tube that isconnected to the vacuum system 636 removes the separated gasses. Morecomplex designs of degasser modules are contemplated, including designshaving serpentine paths of the electrolyte solution across the membraneand other multi-sectioned designs of degasser modules.

Although not shown in FIG. 16, the electrolyte solution replenishingsystem 220 may include a number of other components. For example, theelectrolyte solution replenishing system 220 preferably also includesone or more additional tanks for storage of chemicals for a substratecleaning system, such as the SRD station. Double-contained piping forhazardous material connections may also be employed to provide safetransport of the chemicals throughout the system. Optionally, theelectrolyte solution replenishing system 220 includes connections toadditional or external electrolyte solution processing system to provideadditional electrolyte solution supplies to the electroplating system.

FIG. 17 is a cross sectional view of one embodiment of rapid thermalanneal (RTA) chamber. The RTA chamber 211 is preferably connected to theloading station 210, and substrates are transferred into and out of theRTA chamber 211 by the loading station transfer robot 228. Theelectroplating system, as shown in FIGS. 2 and 3, preferably comprisestwo RTA chambers 211 disposed on opposing sides of the loading station210, corresponding to the symmetric design of the loading station 210.RTA chambers are generally well known in the art, and RTA chambers aretypically utilized in substrate processing systems to enhance theproperties of the deposited materials. The electroplating systemplatform 200 contemplates utilizing a variety of RTA chamber designs,including hot plate designs and heat lamp designs, to enhance theelectroplating results. One particular RTA chamber is the WxZ chamberavailable from Applied materials, Inc., located in Santa Clara, Calif.Although the electroplating system platform 200 is described using a hotplate RTA chamber, other RTA chambers can be used as well.

The RTA chamber 211 generally comprises an enclosure 902, a heater plate904, a heater 907 and a plurality of substrate support pins 906. Theenclosure 902 includes a base 908, a sidewall 910 and a top 912.Preferably, a cold plate 913 is disposed below the top 912 of theenclosure. Alternatively, the cold plate is integrally formed as part ofthe top 912 of the enclosure. Preferably, a reflector insulator dish 914is disposed inside the enclosure 902 on the base 908. The reflectorinsulator dish 914 is typically made from a material such as quartz,alumina, or other material that can withstand high temperatures, i.e.,greater than about 500° C. The reflector insulator dish acts as athermal insulator between the heater 907 and the enclosure 902. The dish914 may also be coated with a reflective material, such as gold, todirect heat back to the heater plate 906.

The heater plate 904 preferably has a large mass compared to thesubstrate being processed in the system. The heater plate is preferablyfabricated from a material such as silicon carbide, quartz, or othermaterials that do not react with any ambient gases in the RTA chamber211 or with the substrate material. The heater 907 typically comprises aresistive heating element or a conductive/radiant heat source and isdisposed between the heated plate 906 and the reflector insulator dish914. The heater 907 is connected to a power source 916 which suppliesthe energy needed to heat the heater 907. Preferably, a thermocouple 920is disposed in a conduit 922, disposed through the base 908 and dish914, and extends into the heater plate 904. The thermocouple 920 isconnected to a controller and supplies temperature measurements to thecontroller. The controller then increases or decreases the heat suppliedby the heater 907 according to the temperature measurements and thedesired anneal temperature.

The enclosure 902 preferably includes a cooling member 918 disposedoutside of the enclosure 902 in thermal contact with the sidewall 910 tocool the enclosure 902. Alternatively, one or more cooling channels, notshown, are formed within the sidewall 910 to control the temperature ofthe enclosure 902. The cold plate 913 disposed on the inside surface ofthe top 912 cools a substrate that is positioned in close proximity tothe cold plate 913.

The RTA chamber 211 includes a slit valve 922 disposed on the sidewall910 of the enclosure 902 for facilitating transfers of substrates intoand out of the RTA chamber. The slit valve 922 selectively seals anopening 924 on the sidewall 910 of the enclosure that communicates withthe loading station 210. The loading station transfer robot 228 shown inFIG. 3 transfers substrates into and out of the RTA chamber through theopening 924.

The substrate support pins 906 preferably comprise distally taperedmembers constructed from quartz, aluminum oxide, silicon carbide, orother high temperature resistant materials. Each substrate support pin906 is disposed within a tubular conduit 926, preferably made of a heatand oxidation resistant material, that extends through the heater plate904. The substrate support pins 906 are connected to a lift plate 928for moving the substrate support pins 906 in a uniform manner. The liftplate 928 is attached to an actuator 930, such as a stepper motor,through a lift shaft 932. The actuator 930 moves the lift plate 928 tofacilitate positioning of a substrate at various vertical positionswithin the RTA chamber. The lift shaft 932 extends through the base 908of the enclosure 902 and is sealed by a sealing flange 934 disposedaround the shaft.

To transfer a substrate into the RTA chamber 211, the slit valve 922 isopened, and the loading station transfer robot 228 extends its robotblade having a substrate positioned thereon through the opening 924 intothe RTA chamber. The robot blade of the loading station transfer robot228 positions the substrate in the RTA chamber above the heater plate904, and the substrate support pins 906 are extended upwards to lift thesubstrate above the robot blade. The robot blade then retracts out ofthe RTA chamber, and the slit valve 922 closes the opening. Thesubstrate support pins 906 are then retracted to lower the substrate toa desired distance from the heater plate 904. Optionally, the substratesupport pins 906 may retract fully to place the substrate in directcontact with the heater plate.

Preferably, a gas inlet 936 is disposed through the sidewall 910 of theenclosure 902 to allow selected gas flow into the RTA chamber 211 duringthe anneal treatment process. The gas inlet 936 is connected to a gassource 938 through a valve 940 for controlling the flow of the gas intothe RTA chamber 211. A gas outlet 942 is preferably disposed at a lowerportion of the sidewall 910 of the enclosure 902 to exhaust the gases inthe RTA chamber. The gas outlet is preferably connected to arelief/check valve 944 to prevent backstreaming of atmosphere fromoutside of the chamber. Optionally, the gas outlet 942 is connected to avacuum pump, not shown, to exhaust the RTA chamber to a desired vacuumlevel during an anneal treatment.

A substrate is annealed in the RTA chamber 211 after the substrate hasbeen electroplated in the electroplating cell and cleaned in the SRDstation. Preferably, the RTA chamber 211 is maintained at aboutatmospheric pressure, and the oxygen content inside the RTA chamber 211is controlled to less than about 100 ppm during the anneal treatmentprocess. Preferably, the ambient environment inside the RTA chamber 211comprises nitrogen (N₂) or a combination of nitrogen (N₂) and less thanabout 4% hydrogen (H₂). The ambient gas flow into the RTA chamber 211 ismaintained at greater than 20 liters/min to control the oxygen contentto less than 100 ppm. The electroplated substrate is preferably annealedat a temperature between about 200° C. and about 450° C. for betweenabout 30 seconds and 30 minutes, and more preferably, between about 250°C. and about 400° C. for between about 1 minute and 5 minutes. RTAprocessing typically requires a temperature increase of at least 50° C.per second. To provide the required rate of temperature increase for thesubstrate during the anneal treatment, the heater plate is preferablymaintained at between about 350° C. and 450° C. The substrate ispreferably positioned at between about 0 mm and about 20 mm from theheater plate (i.e., contacting the heater plate) for the duration of theanneal treatment process. Preferably, a controller 222 controls theoperation of the RTA chamber 211, including maintaining the desiredambient environment in the RTA chamber and the temperature of the heaterplate.

After the anneal treatment process is completed, the substrate supportpins 906 lift the substrate to a position for transfer out of the RTAchamber 211. The slit valve 922 opens, and the robot blade of theloading station transfer robot 228 is extended into the RTA chamber andpositioned below the substrate. The substrate support pins 906 retractto lower the substrate onto the robot blade, and the robot blade thenretracts out of the RTA chamber. The loading station transfer robot 228then transfers the processed substrate into the cassette 232 for removalout of the electroplating processing system as shown in FIGS. 2 and 3.

Referring back to FIG. 2, the electroplating system platform 200includes a controller 222 that controls the functions of each componentof the platform. Preferably, the controller 222 is mounted above themainframe 214, and the controller comprises a programmablemicroprocessor. The programmable microprocessor is typically programmedusing a software designed specifically for controlling all components ofthe electroplating system platform 200. The controller 222 also provideselectrical power to the components of the system and includes a controlpanel 223 that allows an operator to monitor and operate theelectroplating system platform 200. The control panel 223, as shown inFIG. 2, is a stand-alone module that is connected to the controller 222through a cable and provides easy access to an operator. Generally, thecontroller 222 coordinates the operations of the loading station 210,the RTA chamber 211, the SRD station 212, the mainframe 214 and theprocessing stations 218. Additionally, the controller 222 coordinateselectrolyte solution replenishing system 220 to provide the electrolytesolution for the electroplating process.

The following is a description of a typical substrate electroplatingprocess sequence through the electroplating system platform 200 as shownin FIG. 2. A substrate cassette containing a plurality of substrates isloaded into the substrate cassette receiving areas 224 in the loadingstation 210 of the electroplating system platform 200. A loading stationtransfer robot 228 picks up a substrate from a substrate slot in thesubstrate cassette and places the substrate in the substrate orientor230. The substrate orientor 230 determines and orients the substrate toa desired orientation for processing through the system. The loadingstation transfer robot 228 then transfers the oriented substrate fromthe substrate orientor 230 and positions the substrate in one of thesubstrate slots in the substrate pass-through cassette 238 in the SRDstation 212. The mainframe transfer robot 242 picks up the substratefrom the substrate pass-through cassette 238 and positions the substratefor transfer by the flipper robot 248. The flipper robot 248 rotates itsrobot blade below the substrate and picks up substrate from mainframetransfer robot blade. The vacuum suction gripper on the flipper robotblade secures the substrate on the flipper robot blade, and the flipperrobot flips the substrate from a face up position to a face downposition. The flipper robot 248 rotates and positions the substrate facedown in the substrate holder assembly 450. The substrate is positionedbelow the substrate holder element 464 but above the cathode contactring 466. The flipper robot 248 then releases the substrate to positionthe substrate into the cathode contact ring 466. The substrate holderelement 464 moves toward the substrate and the vacuum chuck secures thesubstrate on the substrate holder element 464. The bladder assembly 470on the substrate holder assembly 450 exerts pressure against thesubstrate backside to ensure electrical contact between the substrateplating surface and the cathode contact ring 466.

The head assembly 452 is lowered to a processing position above theprocess cell 420. At this position the substrate is below the upperplane of the weir 478 and contacts the electrolyte solution contained inthe process cell 420. The power supply is activated to supply electricalpower, i.e., voltage and current, to the cathode and the anode to enablethe electroplating process. The electrolyte solution is typicallycontinually pumped into the process cell during the electroplatingprocess. The electrical power supplied to the cathode and the anode andthe flow of the electrolyte solution are controlled by the controller222 to achieve the desired electroplating results. Preferably, the headassembly is rotated as the head assembly is lowered and also during theelectroplating process.

After the electroplating process is completed, the head assembly 410raises the substrate holder assembly and removes the substrate from theelectrolyte solution. Preferably, the head assembly is rotated for aperiod of time to enhance removal of residual electrolyte solution fromthe substrate holder assembly. The vacuum chuck and the bladder assemblyof the substrate holder element then release the substrate from thesubstrate holder element. The substrate holder element is raised toprovide a space to allow the flipper robot blade to enter the space andpick up the processed substrate from the cathode contact ring. Theflipper robot rotates the flipper robot blade above the backside of theprocessed substrate in the cathode contact ring and picks up thesubstrate using the vacuum suction gripper on the flipper robot blade.The flipper robot rotates the flipper robot blade with the substrate outof the substrate holder assembly, flips the substrate from a face-downposition to a face-up position, and positions the substrate on themainframe transfer robot blade. The mainframe transfer robot thentransfers and positions the processed substrate above the SRD module236. The SRD substrate support lifts the substrate, and the mainframetransfer robot blade retracts away from the SRD module 236. Thesubstrate is cleaned in the SRD module using deionized water or acombination of deionized water and a cleaning fluid as described indetail above. The substrate is then positioned for transfer out of theSRD module. The loading station transfer robot 228 picks up thesubstrate from the SRD module 236 and transfers the processed substrateinto the RTA chamber 211 for an anneal treatment process to enhance theproperties of the deposited materials. The annealed substrate is thentransferred out of the RTA chamber 211 by the loading station robot 228and placed back into the substrate cassette for removal from theelectroplating system. The above-described sequence can be carried outfor a plurality of substrates substantially simultaneously in theelectroplating system platform 200. Also, the electroplating system canbe adapted to provide multi-stack substrate processing.

2. Mainframe Structure and Operation

FIGS. 2, 3, and 6 show one embodiment of the mainframe 214. In oneembodiment, the mainframe 214 comprises an upper mainframe, a lowermainframe, and a dampener. FIG. 27 shows a detailed view of oneembodiment of the upper mainframe 20 2700 of the mainframe. FIG. 28shows a detailed view of one embodiment of the lower mainframe 2840 anddampener system 2802 of the mainframe. During operation, the uppermainframe 2700 is supported by the dampener system 2802 and the lowermainframe 2840. The upper mainframe 2700 contains recesses 2708 that areadapted to surround the process cells 420 shown in FIG. 6. In thisdisclosure, the structure of the upper mainframe 2700 is describedrelative to FIGS. 27 and 29. The structure of the lower mainframe 2840and the dampener system 2802 is described relative to FIGS. 28 and 30.The relative operation of the upper mainframe 2700, the lower mainframe2840, and the dampener system 2802 is also described with reference toFIGS. 27-30. As such, FIGS. 27 to 30 should be viewed in combinationrelative to the entire mainframe

The upper mainframe 2700, one embodiment of which is shown in FIG. 27,comprises a main base plate 2702 and a plurality of attached rigidifyingplates 2704. The main base plate 2702 comprises a robot mount 2710positioned near the center, a plurality of inner support mounts 2714, aplurality of outer support mounts 2712, and a plurality of recesses2708. The robot mount contains a robot mount flange 2760 that supportsthe mainframe transfer robot 242 as shown in FIG. 24, typically bybolts, welds, or other known fasteners. The recesses 2708 are sized toreceive process cells 420. The inner support mounts 2714 and the outersupport mounts 2712 are configured to be secured to portions of theaxially extending support members 2804, 2806 of the dampener system 2802as described below.

One side of each rigidifying plate 2704 is secured to abut a side of themain base plate 2702. The rigidifying plates 2704 strengthen the uppermainframe to enhance the structural support of the process cells withinthe upper mainframe. One embodiment of the rigidifying plate 2704 isshown in detail in FIG. 29. The rigidifying plate 2704 comprises outersupport mounts 2712, an aperture 2718 formed therein, a fastenerstructure 2720, and fasteners 2730. Alternatively, the fastenerstructure 2720 may be attached to the recess 2708, shown in FIG. 27, inthe main base plate 2702 or between the main base plate 2702 and therigidifying plate 2704. In those embodiments that the fastener structure2740 is positioned between the rigidifying plate 2704 and the main baseplate 2702, the fasteners 2730 may be loosened to permit adjustment ofthe fastener structure 2720. Such adjustment may occur after the processcell is mounted on the fastener structure by, for example, bolts, andeach process cell can then be displaced laterally to a desired position.Displacement of the fastener structure in this manner provides forrelative adjustments to be made between different process cells. Afterthe fastener structure is adjusted, the fasteners 2730 are retightenedto maintain the position of the process cell.

Alternatively, recess 2708 formed in the main base plate 2702 can beprovided with a horizontal cross-sectional area that is almost as largeas the rigidifying plate 2704. The aperture 2718 supports the mass ofone or more process cells, and the main base plate 2702 supports themass of the rigidifying plate 2704. The thickness of the rigidifyingplate 2704 in these embodiments is then sufficient to support the weightof the process cells without additional support from the main base plate2702.

FIG. 28 shows a perspective view of the lower mainframe 2840 and adampener system 2802. The dampener system 2802 comprises a plurality ofouter axially extending support members 2804 and a plurality of inneraxially extending support members 2806. The lower mainframe 2840comprises a substantially rectangular outer frame 2801, a plurality ofcross members 2803, and a plurality of brace members 2805. The pluralityof cross members 2803 extend between, and are attached to the outerframe 2801. The plurality of brace members 2805 extend between and areattach to the cross members 2803. The outer axially extending members2804 are mounted to the outer frame 2801 as shown in FIG. 28. The inneraxially extending support members 2806 are mounted to the different onesof the cross members 2803. Each inner axially extending support member2806 is attachable to one inner support mounts 2714 of the uppermainframe 2700 shown in FIG. 27. Similarly, each outer axially extendingsupport members 2804 is attachable to one outer support mounts 2712 ofthe upper mainframe 2700.

FIG. 30 shows an expanded, partial cross-sectional, view of a portion ofthe dampener system 2802 showing one outer axially extending supportmember 2804 and one inner axially extending support member 2806. Moreparticularly, FIG. 30 shows a side view of one embodiment of an outeraxially extending support member 2804 and a cross sectional view of oneembodiment of an inner axially support member 2806. Both the outeraxially extending support members 2804 and the inner axially supportmembers 2806 are connected to the lower mainframe 2840. The inneraxially support member 2806, comprises a hollow tubular member 2820, apiston member 2822, and a dampening element 2824. The hollow tubularmember 2820 is generally cylindrical, although different configurationssuch as rectangular, oblong, etc. may be utilized. The dampening element2824 is disposed within, and fills the hollow tubular member 2820 tonearly its upper limit. The hollow tubular member is sealed at itsbottom 2850 to limit the dampening element 2824 from escaping throughthe bottom of the inner axially support member 2806. The piston member2822 comprises a piston segment 2852 and a fastener segment 2854. Thefastener segment 2854 of the piston member 2822 may be attached to theinner support mount 2714 as shown in FIG. 27. The outer axiallyextending support member 2804 is preferably structurally similar to theinner axially extending support member 2806.

Downward force on the upper mainframe 2700 is directed through the outersupport mounts 2712 and the inner support mounts 2714 to the pistonmember 2822 associated with the outer axially extending support member2804 and inner axially extending support member 2806, respectively bysuch fasteners as screws, bolts, welds, attachments, adhesives, etc. Thedownward force is applied to the piston member 2822 from the uppermainframe 2700. The downward force is applied from, for example, theprocess cells contained within the recesses 2708, and supported by thefastener structure 2720. The force applied to the piston segment 2852 isdirected against the dampening element 2824, which compresses to acertain degree. However, the compressibility of the dampening element2824 is relatively limited. For example, sand may be used as thedampening element 2824, though alternate granular or resilient materialmay be used. The dampening element 2824 is configured to dampenoscillations of the process cells at the natural frequency of theprocess cells. For example, the naturaly frequencies of the processcells are typically in the about 10 to about 200 Hz range, and moreparticularly in the about 50 to 65 Hz range.

The axially extending support members 2804 and 2806 include thedampening element 2824 to limit the transmission of the vibrationsbetween the upper mainframe 2700 to the lower mainframe 2840. Thedampening element 2824 acts to deaden many frequencies applied from thelower mainframe through the axially extending support member 2806 and2804 and the piston members 2822 to the upper mainframe 2700. Thedampener system 2802 also acts to isolate the vibrations anddisplacements that are transmitted from the upper mainframe to the lowermainframe 2840. For example, certain motors and actuators may bepositioned in close proximity to the lower mainframe and/or the uppermainframe 2700, and apply vibrations thereto.

Since multiple process cells 420 are mounted to the various fastenerstructures 2706 within the single upper mainframe 2700, the uppermainframe 2700 supports the weight of all of the process cells. Themomentum necessary to displace or vibrate the upper mainframe 2700supporting a plurality of process cells is greater than the momentumnecessary to displace a single support a main frame associated with asingle process cell. The entire mainframe including the process cells istherefore a considerable mass. Due to the large mass of the mainframe, aconsiderable directed force is necessary to provide a given vibration.The vibrations and/or displacements applied to the different ones of theprocess cells most likely act in different, likely orthogonal,directions, and therefore different ones of the forces applied todifferent ones of the process cells act to cancel. Even if thevibrations or displacements are not canceled out, the dampener system2802, comprising the inner axially extending support members 2806 andthe outer axially extending support members 2804, dampens the vibrationsor displacements.

The above description relates the mainframe, including the uppermainframe, the lower mainframe, and the dampener system, to an ECPsystem. By comparison, the above mainframe structure could be applied toprocess cells in such systems as PVD, CVD, CMP, etc. The mainframestructure could also be used in metrology cells that are used to measureor inspect substrates.

While the foregoing is directed to the preferred embodiment of thepresent invention, other and further embodiments of the invention may bedevised without departing from the basic scope thereof.

1. A platform to support a cell, comprising: a lower mainframe; an uppermainframe including a plurality of recesses, each one of the pluralityof recesses configured to receive a cell, wherein the upper mainframecomprises a fastener structure positioned proximate each one of therecesses, wherein the fastener structure is configured to hold the cell;and a dampener system connecting the lower mainframe to the uppermainframe, wherein the dampener system comprises a plurality of supportmembers that extend between the lower mainframe and the upper mainframe,wherein each support member composes: a hollow tubular member, a pistonslidably disposed within the hollow tubular member, and a dampeningelement contained within the hollow tubular member, wherein the pistonis biased against the dampening element.
 2. A platform to support acell, comprising: a lower mainframe; an upper mainframe including aplurality of recesses, each one of the plurality of recesses configuredto receive a cell, wherein the upper mainframe comprises a rigidifyingplate and a main base plate comprising the plurality of recesses, therigidifying plate comprising at least one aperture and attached to themain base plate such that the at least one aperture is aligned with therecesses; and a dampener system connecting the lower mainframe to theupper mainframe, wherein the dampener system comprises a plurality ofsupport member that extend between the lower mainframe and the uppermainframe, wherein each support member comprises: a hollow tubularmember, a piston slidably disposed within the hollow tubular member, anda dampening element contained within the hollow tubular member, whereinthe piston is based against the dampening element.